Does Bariatric Surgery Affect Kidney Transplant Risks?

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Available data suggest that patients with previous bariatric surgery are not at increased risk of complications or adverse outcomes after kidney transplantation, reports a meta-analysis in Transplantation.

A literature review identified 18 studies reporting on the outcomes of kidney transplantation in 315 patients with previous bariatric surgery. Approximately two-thirds of patients underwent sleeve gastrectomy, and most of the others underwent Roux-en-Y gastric bypass. Quality was rated good in all but one study. Data were pooled for meta-analysis of kidney transplant outcomes.

Reported percentage of excess weight loss was 46.3%–94.8%, with a mean of 62.8%. Delayed graft function and acute rejection each occurred in 16% of patients, based on reported data from 14 and 11 studies, respectively. Wound complications occurred in 5% of patients (from 12 studies), urinary complications in 19% (from 9 studies), and vascular complications in 2% (from 11 studies).

Eleven studies reported kidney transplant outcomes at follow-up times from 15 months to over 5 years. Based on data from 14 studies, the average rate of graft loss was 3%. In four studies reporting a comparison group of patients with obesity who underwent kidney transplantation without previous bariatric surgery, transplant outcomes and complications were similar between groups.

Obesity-related diseases are a major contributor to end stage kidney disease, and weight loss can improve access to kidney transplantation in patients with obesity. Although bariatric surgery has been suggested as a bridge to kidney transplant, its impact on transplant outcomes is unclear.

The new meta-analysis suggests that the outcomes of kidney transplantation after bariatric surgery are similar to those in other transplant recipients. The researchers emphasize the “urgent need” for larger, well-designed studies to clarify whether there are beneficial effects of bariatric surgery on kidney transplant outcomes [Pencovich N, et al. Outcomes of kidney transplantation in patients that underwent bariatric surgery: A systematic review and meta-analysis. Transplantation, published online ahead of print June 5, 2023. doi: 10.1097/TP.0000000000004680;].